Try using one of the HTTP::Cookies derivatives such as HTTP::Cookies::Netscape or HTTP::Cookies::Microsoft depending on the browser that you are using. You can pre-populate cookies using your browser and then use them in your script.
Remember that session cookies will be deleted when a browser session ends. It may be the case that you need to get your script to do the login part in order to generate the session cookies that are later used in the script. Check out WWW::Mechanize as a means of logging in using a form etc.